Physical Fitness and Physical Activity in Adolescent Childhood Cancer Survivors and Controls: The PACCS Study.

OBJECTIVES To compare physical fitness, function and physical activity (PA) in adolescent childhood cancer survivors (CCSs) to age- and sex-matched controls and across different cancer diagnoses. METHODS This multicenter cross-sectional study (PACCS) included CCSs aged 9-18 years (≥1-year after cancer treatment) and age- and sex-matched controls. Physical fitness tests included cardiorespiratory fitness (VO2max) and muscular strength (maximal isometric handgrip, knee-extension, and chest-press). Physical function tests included a 1-min sit-to-stand test (STS) and countermovement jump (CMJ). PA was measured by accelerometer for seven days. We used linear mixed effects models to compare outcomes between CCSs and controls, and across diagnostic groups. RESULTS We included 157 CCSs and 113 controls, aged 13.4 ± 2.6 years (mean ± SD). Cancer types were leukemia (n = 78), central nervous system (CNS) tumors (n = 18), lymphoma (n = 16), and other solid tumors (n = 45). CCSs had lower VO2max (marginal mean [95% confidence interval]) 41.7 [38.4-45.0] vs 46.4 [42.9-49.8] mL·kg-1·min-1, P < 0.001), knee-extension strength (35.4 [34.1-36.8] vs 38.2 [36.7-39.7] kg, P = 0.003), chest-press strength (30.0 [28.4-31.6] vs 32.8 [31.0-34.7] kg, P = 0.007), STS repetitions (57.5 [55.8-59.3] vs 60.0 [58.0-62.0] P = 0.017), and CMJ height (22.1, [20.5-23.8] vs 24.9 [23.2-26.6] cm, P < 0.001). PA levels and sedentary time were similar in both groups (8513 [7993-9034] vs 9000 [8404-9596] steps per day, P = 0.174, respectively). Survivors of CNS tumors had the lowest values for VO2max, muscular strength, physical function and PA. CONCLUSIONS Despite no significant difference in PA levels, adolescent CCSs had 4.2% to 11% lower physical fitness and function compared to controls, where survivors of CNS tumors performed poorest.